From d088e3c1286b548a58e62afdc70bb40981cdb9e8 Mon Sep 17 00:00:00 2001
From: Nathan Kidd <nkidd@opentext.com>
Date: Fri, 9 Jan 2015 10:04:41 -0500
Subject: Xi: integer overflow and unvalidated length in
 (S)ProcXIBarrierReleasePointer

[jcristau: originally this patch fixed the same issue as commit
 211e05ac85 "Xi: Test exact size of XIBarrierReleasePointer", with the
 addition of these checks]

This addresses CVE-2017-12179

Reviewed-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Reviewed-by: Jeremy Huddleston Sequoia <jeremyhu@apple.com>
Reviewed-by: Julien Cristau <jcristau@debian.org>
Signed-off-by: Jeremy Huddleston Sequoia <jeremyhu@apple.com>
Signed-off-by: Nathan Kidd <nkidd@opentext.com>
Signed-off-by: Julien Cristau <jcristau@debian.org>

diff --git a/Xi/xibarriers.c b/Xi/xibarriers.c
index d82ecb6..d0be701 100644
--- a/Xi/xibarriers.c
+++ b/Xi/xibarriers.c
@@ -834,6 +834,8 @@ SProcXIBarrierReleasePointer(ClientPtr client)
     REQUEST_AT_LEAST_SIZE(xXIBarrierReleasePointerReq);
 
     swapl(&stuff->num_barriers);
+    if (stuff->num_barriers > UINT32_MAX / sizeof(xXIBarrierReleasePointerInfo))
+        return BadLength;
     REQUEST_FIXED_SIZE(xXIBarrierReleasePointerReq, stuff->num_barriers * sizeof(xXIBarrierReleasePointerInfo));
 
     info = (xXIBarrierReleasePointerInfo*) &stuff[1];
@@ -856,6 +858,9 @@ ProcXIBarrierReleasePointer(ClientPtr client)
     xXIBarrierReleasePointerInfo *info;
 
     REQUEST(xXIBarrierReleasePointerReq);
+    REQUEST_AT_LEAST_SIZE(xXIBarrierReleasePointerReq);
+    if (stuff->num_barriers > UINT32_MAX / sizeof(xXIBarrierReleasePointerInfo))
+        return BadLength;
     REQUEST_FIXED_SIZE(xXIBarrierReleasePointerReq, stuff->num_barriers * sizeof(xXIBarrierReleasePointerInfo));
 
     info = (xXIBarrierReleasePointerInfo*) &stuff[1];
-- 
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